1. Field of the Invention
The present invention relates generally to apparatus and methods for dechucking substrates from electrostatic chucks. More particularly, the present invention relates to apparatus and methods for efficiently dechucking substrates from electrostatic chucks.
2. Description of the Related Art
Microelectronic fabrications are formed from microelectronic substrates over which are formed patterned microelectronic conductor layers which are separated by microelectronic dielectric layers.
Within the fabrication of microelectronic fabrications, and in particular within the fabrication of semiconductor integrated circuit microelectronic fabrications, there are employed various fabrication processes which in general require that a microelectronic fabrication substrate be held in a fixed position within a microelectronic fabrication apparatus under circumstances where the microelectronic fabrication substrate is fabricated, or otherwise processed, within the microelectronic fabrication apparatus. Examples of such microelectronic fabrication processes include, but are not limited to, microelectronic fabrication inspection processes, microelectronic fabrication spin coating processes, microelectronic fabrication vacuum etch processes and microelectronic fabrication vacuum deposition processes.
In order to hold a microelectronic fabrication substrate in a fixed position with respect to a microelectronic fabrication apparatus when fabricating or otherwise processing the microelectronic fabrication substrate within the microelectronic fabrication apparatus, there is often employed within the microelectronic fabrication apparatus an electrostatic chuck upon which the microelectronic fabrication substrate is positioned and fixed by action of an electrostatic charge introduced within the electrostatic chuck. As is understood by a person skilled in the art, the electrostatic charge introduced within the electrostatic chuck concurrently induces a corresponding complementary electrostatic charge within the microelectronic fabrication substrate positioned, electrically isolated, and thus electrostatically fixed, upon the electrostatic chuck.
While electrostatic chucks are thus clearly desirable in the art of microelectronic fabrication for fixing a position of a microelectronic fabrication substrate with respect to a microelectronic fabrication apparatus when fabricating or otherwise processing the microelectronic fabrication substrate, electrostatic chucks are nonetheless not entirely without problems in the art of microelectronic fabrication when employed for fixing a position of a microelectronic fabrication substrate with respect to a microelectronic fabrication apparatus when fabricating or otherwise processing the microelectronic fabrication substrate. In that regard, when employing within the art of microelectronic fabrication an electrostatic chuck for purposes of fixing a position of a microelectronic fabrication substrate with respect to a microelectronic fabrication apparatus when fabricating or otherwise processing a microelectronic fabrication substrate, it is often difficult to remove (i.e., dechuck) the microelectronic fabrication substrate from the electrostatic chuck after having fabricated or otherwise processed the microelectronic fabrication substrate within the microelectronic fabrication apparatus, typically insofar as it is often difficult to fully and efficiently dissipate an electrostatic charge within the microelectronic fabrication substrate positioned and electrostatically fixed upon the electrostatic chuck.
It is thus desirable in the art of microelectronic fabrication to provide electrostatic chuck apparatus and electrostatic chuck dechucking methods which provide for more efficient dechucking of microelectronic fabrication substrates from electrostatic chucks.
It is towards the foregoing object that the present invention is more specifically directed.
Various electrostatic chuck apparatus and electrostatic chuck dechucking methods have been disclosed within arts including but not limited to microelectronic fabrication arts for assisting in removal of substrates, including but not limited to microelectronic fabrication substrates, from electrostatic chucks.
Representative electrostatic chuck apparatus and electrostatic chuck dechucking methods are disclosed within, but not limited to: (1) Shel, U.S. Pat. No. 5,790,365 (an electrostatic chuck apparatus and an electrostatic chuck dechucking method which employ an inductor/intrinsic capacitor tank circuit to assist in dechucking of a substrate from an electrostatic chuck); (2) Kumar et al., U.S. Pat. No. 5,880,924 (an electrostatic chuck apparatus and an electrostatic chuck dechucking method which employ within an electrostatic chuck: (1) a fixed charging electrode for generating an electrostatic charge within the electrostatic chuck and a substrate positioned and fixed upon the electrostatic chuck; and (2) a separate fixed discharge electrode for dissipating the electrostatic charge from within the electrostatic chuck and the substrate positioned and fixed upon the electrostatic chuck); (3) Lowenhardt et al., U.S. Pat. No. 5,900,062 (an electrostatic chuck apparatus and an electrostatic chuck dechucking method which employ a conductive lift pin connected to electrical ground through a radio frequency current filter or a resistive radio frequency voltage attenuator to assist in dechucking of a substrate from an electrostatic chuck); and (4) Brown, U.S. Pat. No. 6,104,595 (an electrostatic chuck apparatus and an electrostatic chuck dechucking method which employ a photoconductive material for fabricating an electrostatic chuck such as to photofacilitatively assist in dechucking a substrate from an electrostatic chuck).
Desirable within arts including but not limited to microelectronic fabrication arts are additional electrostatic chuck apparatus and electrostatic chuck dechucking methods which provide for efficient dechucking of substrates from electrostatic chucks.
It is towards the foregoing object that the present invention is more generally directed.
A first object of the present invention is to provide an electrostatic chuck apparatus and an electrostatic chuck dechucking method for dechucking a substrate from an electrostatic chuck which comprises the electrostatic chuck apparatus.
A second object of the present invention is to provide the electrostatic chuck apparatus and the electrostatic chuck dechucking method in accord with the first object of the present invention, wherein there is provided an efficient dechucking of the substrate from the electrostatic chuck which comprises the electrostatic chuck apparatus.
A third object of the present invention is to provide the electrostatic chuck apparatus and the electrostatic chuck dechucking method in accord with the first object of the present invention and the second object of the present invention, wherein the electrostatic chuck apparatus is readily fabricated and the electrostatic chuck dechucking method is readily commercially implemented.
In accord with the objects of the present invention, there is provided by the present invention an electrostatic chuck apparatus and a method for fabricating a substrate while employing a fabrication apparatus having assembled therein the electrostatic chuck apparatus.
To practice the method of the present invention, there is first provided a fabrication tool having assembled therein an electrostatic chuck apparatus comprising: (1) an electrostatically energizable substrate plate sized to accommodate a substrate; and (2) an electrically conductive lift pin movably positionable with respect to the electrostatically energizable substrate plate such as to optionally contact and lift the substrate when positioned upon the electrostatically energizable substrate plate. Within the present invention, the electrically conductive lift pin is connected to ground through a switch. There is then positioned the substrate upon the electrostatically energizable substrate plate with the electrically conductive lift pin not contacting the substrate and with the switch open. There is also electrostatically energized the electrostatically energizable substrate plate. There is then fabricated the substrate while employing the fabrication tool at least in part with the electrostatically energizable substrate plate electrostatically energized. Finally, there is then repositioned the electrically conductive lift pin to contact the substrate, while closing the switch.
The method for fabricating the substrate while employing the fabrication apparatus having assembled therein the electrostatic chuck apparatus in accord with the present invention contemplates the electrostatic chuck apparatus which may be employed within the method for fabricating the substrate while employing the fabrication apparatus having assembled therein the electrostatic chuck apparatus in accord with the present invention.
The present invention provides an electrostatic chuck apparatus and a method for fabricating a substrate while employing a fabrication apparatus having assembled therein the electrostatic chuck apparatus, wherein there is provided efficient dechucking of the substrate positioned and fixed upon an electrostatic chuck which comprises the electrostatic chuck apparatus.
The present invention realizes the foregoing objects by employing when fabricating a substrate while employing a fabrication apparatus having assembled therein the electrostatic chuck apparatus, and in particular with respect to the electrostatic chuck apparatus: (1) an electrostatically energizable substrate plate sized to accommodate a substrate; and (2) an electrically conductive lift pin movably positioned with respect to the electrostatically energizable substrate plate such as to optionally contact and lift the substrate when positioned upon the electrostatically energizable substrate plate, further where the electrically conductive lift pin is connected to ground through a switch. By employing when fabricating the substrate while employing the fabrication apparatus having assembled therein the electrostatic chuck apparatus in accord with the present invention the foregoing: (1) electrostatically energizable substrate plate; and (2) electrically conductive lift pin, and incident to: (1) positioning the substrate upon the electrostatically energizable substrate plate; (2) electrostatically energizing the electrostatically energizable substrate plate; (3) fabricating the substrate with the electrically conductive lift pin not contacting the substrate and with the switch open; and (4) deenergizing the electrostatically energizable substrate plate; (5) the electrically conductive lift pin may be repositioned to contact the substrate, while closing the switch, such as to effect a more efficient dechucking of the substrate from an electrostatic chuck (i.e., the electrostatically energizable substrate plate) which comprises the electrostatic chuck apparatus.
The electrostatic chuck apparatus of the present invention is readily fabricated and the electrostatic chuck apparatus dechucking method of the present invention is readily commercially implemented.
The present invention employs fabrication apparatus components as are otherwise generally known within arts including but not limited to microelectronic fabrication arts, or generally available within arts including but not limited to microelectronic fabrication arts, but employed within the context of a specific electrostatic chuck apparatus construction of the present invention employed within a specific electrostatic chuck apparatus dechucking method of the present invention. Since it is thus at least in part a specific assemblage of components which provides at least in part the present invention, rather than the existence of specific components which provides the present invention, the electrostatic chuck apparatus of the present invention is readily fabricated and the electrostatic chuck apparatus dechucking method of the present invention is readily commercially implemented.